Remote control device



. May-4, 1943. J. M. TEWKSB-URY I REMOTE CONTROL DEVICE Filed April 16, 1941 51in Merle Yw/hshuy A Home Patented May4. 1943 John Merlev Tewksbllr signor of forty per twenty per cent to Skowhegan. Maine 7, Skowhegan, Maine, ascent to Robert Lyons and George M. Davis, both of Application April 16, 19%1, Serial No. 388,911

IClalm.

My invention relates to improve'ments in electrical remote control means of the type enabling selection for operation of a circuit or circuits at a point remote from a device, and the primary object of the invention is to provide a simple and emcient arrangement of this character.

Other important objects and advantages of my invention will be apparent from a reading of the following description taken in connection with the appended drawing, wherein for purposes of illustration I have shown a preferred embodiment of my invention.

In the drawing- Figure l is ageneral schematic wiring diagram showing a device in accordance with the present invention.

Figure 2 is an elevational view of the electrically operated stepper."

Referring in detail to the drawing, the numerals 8 designate each of a plurality of solenoids or other electrical agencies which are severally connected to the corresponding contacts a", b", c", d", etc., and to a common conductor 8 leading from one side of a source of operating voltage diagrammatically represented at I, the remaining side of the source I being connected intermediate the ends of the line I leading to the remotely located selecting means. The said contacts are located concentrically with respect to another arcuate series of contacts a, b, c, d, etc., which are radially aligned with the ilrstmentioned contacts. Connected between adjacent ones of the contacts a, b, c, d, etc., are resistors, each of which is of a capacity of about 10,000 ohms." The contact 1' .is connected to the line ll companion to the line leading to the remote selecting means.

Pivotally' supported at the center of the two, series of contacts and resistors is the conductive arm ll of the stepper mechanism which is generally designated l2 and which comprises the ratchet wheel It, the solenoid core including the pivoted dog it to feed the ratchet wheel II in the direction of the arrow, and the pawl it normally preventing return rotation of the ratchet, wheel H by suitable means (not shown) provided for this purpose, except when the pawl It is plate supDLv. The armature II of the relay is normally retracted away from the relay coil by a spring 22 so as to be out of engagement with the contact 23 which is connected at N to the solenoid ll of the stepper I! through its circuit breaker 25. The remaining end of the solenoid I4 is connected to a current source 20 which is connected to the relay armature II. The heater of the tube H has one side grounded at 21 and the other side connected to a suitable heater supply source.

lifted out of engagement with the wheel I! in resetting the mechanism. The line 8 is connected to the arm II as indicated in Figure 1 of the drawing.

Connected to the line 8 at it is the grid of a vacuum tube I'I whose plate ll is connected at I l to'one end of the coil of the relay 2! whose remaining end is connected to positive of suitable In the line III are connected the resistors II and- 20 which have a ground between them and a power source 3| connected to the line I. outside of the resistors at the points indicated by the numerals 32() and 3I(+). In an experimental embodiment of the invention the values of the resistors 20 and II were such as to produce 300 volts across the resistor 20 which was 20 volts less than the voltage across the resistor II. Beyond the resistors 20 and II the line II is connected to the contact i which is the last one of a circular series of contacts a, b, c, d, e. I, 0. h, and i which have resistors 0' similar in capacity to the resistors 9 already described, connected between the adjacent ones of the contacts. At the center of curvature of the series of contacts is pivoted the switch arm 84 which has a suitable handle 3! projecting therefrom to operate the K switch arm 34 to engage selectively with the a various contacts in accordance with which one of the solenoids or other electrical elements it is desired to select for operation at a point remote from the selecting means comprising the switch arm :4 and the handle II. The line I I is connected to the switch arm it through a suitable switch It is evident from the foregoing that the sums of the resistors decrease downwardly from the upper ends of the semi-circular series.

' Operation Supposing it is desired to select for operation this point. The plate current of the tube flows in the tube and causes the-relay 10' to close, thereby causing the stepper l2 tooperate the conductive arm II in the direction indicated by the arrow so as to cut down the total of the resistances 9. The current in theplate circuit of the tube ii continues to flow as the resistance on the resistors 9. Thevqltage at this point on the grid of the tube will be about 10 volts negative with respect to its filament. This 10 volts negative acts as a bias on the grid and causes the plate current to cease flowing to the relay, so that the relay armature opens by the action of the spring 22, thereby stopping the stepper public coin controlled phonograph, the solenoids 5- maybe of well known selector solenoid type, but the invention is not, of course, restricted to any particular form of apparatus to be selectively operated;

While the switch 36 is openthe voltage on the grid of the vacuum tube ii is approximately 160 volts negative with respect to its filament, and plate current does not flow in the tube ill and the relay 2@ remains open. In this position oi the parts the arm ii of .the stepper unit 02 is engaged with the contacts a and a," with all of the resistanceof the series 9 cut in. After an is thus reduced until a point in the travel of the arm l i is reached at which the capacity of the resisters 9 equals the capacity of the selected point operation of the device as described, resetting of i the arm H is accomplished by retracting the pawl 95 and allowing the ratchet wheel it to be returned-to its initial position by suitable means (not shown) provided for this purpose.

Although I have shown and described herein a preferred emimdiment of my invention, it is to be definitely understood that I do not wish to limit the application of my invention thereto. except as may be required by the scope of the subjoined claim.

Having described the claimed as new is In a-self-balancing Wheatstone bridge circuit including a local resistor and a remote resistor, electrical elements connected for energizatlon to corresponding points along said remote resistor, an electro-magnetic ratchet stepper comprising invention, what is a separately energized circuit including a circuit breaker including means in said circuit between said local resistor and said remote resistor, an adjustable contactor for said local resistor con.- nected between said local resistor and said stepper, said stepper comprising a contactor engaging said remote resistor to be moved step by step along said remote resistor as the stepper is op- -erated to points bn said remote resistor electrically' corresponding to the points on said local resistor to which, its contactor is successively adjusted, and a vacuum tube operated relay circuit operatively connected between said adjustable contactor and said stepper.-

JOHN MERLE rnwrrsaunr. 

